/* * Simplest possible simple frame-buffer driver, as a platform device * * Copyright (c) 2013, Stephen Warren * * Based on q40fb.c, which was: * Copyright (C) 2001 Richard Zidlicky <rz@linux-m68k.org> * * Also based on offb.c, which was: * Copyright (C) 1997 Geert Uytterhoeven * Copyright (C) 1996 Paul Mackerras * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for * more details. */ #include <linux/errno.h>#include <linux/fb.h>#include <linux/io.h>#include <linux/module.h>#include <linux/platform_data/simplefb.h>#include <linux/platform_device.h>#include <linux/clk-provider.h>#include <linux/of_platform.h> static struct fb_fix_screeninfo simplefb_fix = {	.id		= "simple",	.type		= FB_TYPE_PACKED_PIXELS,	.visual		= FB_VISUAL_TRUECOLOR,	.accel		= FB_ACCEL_NONE,}; static struct fb_var_screeninfo simplefb_var = {	.height		= -1,	.width		= -1,	.activate	= FB_ACTIVATE_NOW,	.vmode		= FB_VMODE_NONINTERLACED,}; #define PSEUDO_PALETTE_SIZE 16 static int simplefb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,			      u_int transp, struct fb_info *info){	u32 *pal = info->pseudo_palette;	u32 cr = red >> (16 - info->var.red.length);	u32 cg = green >> (16 - info->var.green.length);	u32 cb = blue >> (16 - info->var.blue.length);	u32 value; 	if (regno >= PSEUDO_PALETTE_SIZE)		return -EINVAL; 	value = (cr << info->var.red.offset) |		(cg << info->var.green.offset) |		(cb << info->var.blue.offset);	if (info->var.transp.length > 0) {		u32 mask = (1 << info->var.transp.length) - 1;		mask <<= info->var.transp.offset;		value |= mask;	}	pal[regno] = value; 	return 0;} static void simplefb_destroy(struct fb_info *info){	if (info->screen_base)		iounmap(info->screen_base);} static struct fb_ops simplefb_ops = {	.owner		= THIS_MODULE,	.fb_destroy	= simplefb_destroy,	.fb_setcolreg	= simplefb_setcolreg,	.fb_fillrect	= cfb_fillrect,	.fb_copyarea	= cfb_copyarea,	.fb_imageblit	= cfb_imageblit,}; static struct simplefb_format simplefb_formats[] = SIMPLEFB_FORMATS; struct simplefb_params {	u32 width;	u32 height;	u32 stride;	struct simplefb_format *format;}; static int simplefb_parse_dt(struct platform_device *pdev,			   struct simplefb_params *params){	struct device_node *np = pdev->dev.of_node;	int ret;	const char *format;	int i; 	ret = of_property_read_u32(np, "width", &params->width);	if (ret) {		dev_err(&pdev->dev, "Can't parse width property\n");		return ret;	} 	ret = of_property_read_u32(np, "height", &params->height);	if (ret) {		dev_err(&pdev->dev, "Can't parse height property\n");		return ret;	} 	ret = of_property_read_u32(np, "stride", &params->stride);	if (ret) {		dev_err(&pdev->dev, "Can't parse stride property\n");		return ret;	} 	ret = of_property_read_string(np, "format", &format);	if (ret) {		dev_err(&pdev->dev, "Can't parse format property\n");		return ret;	}	params->format = NULL;	for (i = 0; i < ARRAY_SIZE(simplefb_formats); i++) {		if (strcmp(format, simplefb_formats[i].name))			continue;		params->format = &simplefb_formats[i];		break;	}	if (!params->format) {		dev_err(&pdev->dev, "Invalid format value\n");		return -EINVAL;	} 	return 0;} static int simplefb_parse_pd(struct platform_device *pdev,			     struct simplefb_params *params){	struct simplefb_platform_data *pd = dev_get_platdata(&pdev->dev);	int i; 	params->width = pd->width;	params->height = pd->height;	params->stride = pd->stride; 	params->format = NULL;	for (i = 0; i < ARRAY_SIZE(simplefb_formats); i++) {		if (strcmp(pd->format, simplefb_formats[i].name))			continue; 		params->format = &simplefb_formats[i];		break;	} 	if (!params->format) {		dev_err(&pdev->dev, "Invalid format value\n");		return -EINVAL;	} 	return 0;} struct simplefb_par {	u32 palette[PSEUDO_PALETTE_SIZE];#if defined CONFIG_OF && defined CONFIG_COMMON_CLK	int clk_count;	struct clk **clks;#endif}; #if defined CONFIG_OF && defined CONFIG_COMMON_CLK/* * Clock handling code. * * Here we handle the clocks property of our "simple-framebuffer" dt node. * This is necessary so that we can make sure that any clocks needed by * the display engine that the bootloader set up for us (and for which it * provided a simplefb dt node), stay up, for the life of the simplefb * driver. * * When the driver unloads, we cleanly disable, and then release the clocks. * * We only complain about errors here, no action is taken as the most likely * error can only happen due to a mismatch between the bootloader which set * up simplefb, and the clock definitions in the device tree. Chances are * that there are no adverse effects, and if there are, a clean teardown of * the fb probe will not help us much either. So just complain and carry on, * and hope that the user actually gets a working fb at the end of things. */static int simplefb_clocks_init(struct simplefb_par *par,				struct platform_device *pdev){	struct device_node *np = pdev->dev.of_node;	struct clk *clock;	int i, ret; 	if (dev_get_platdata(&pdev->dev) || !np)		return 0; 	par->clk_count = of_clk_get_parent_count(np);	if (par->clk_count <= 0)		return 0; 	par->clks = kcalloc(par->clk_count, sizeof(struct clk *), GFP_KERNEL);	if (!par->clks)		return -ENOMEM; 	for (i = 0; i < par->clk_count; i++) {		clock = of_clk_get(np, i);		if (IS_ERR(clock)) {			if (PTR_ERR(clock) == -EPROBE_DEFER) {				while (--i >= 0) {					if (par->clks[i])						clk_put(par->clks[i]);				}				kfree(par->clks);				return -EPROBE_DEFER;			}			dev_err(&pdev->dev, "%s: clock %d not found: %ld\n",				__func__, i, PTR_ERR(clock));			continue;		}		par->clks[i] = clock;	} 	for (i = 0; i < par->clk_count; i++) {		if (par->clks[i]) {			ret = clk_prepare_enable(par->clks[i]);			if (ret) {				dev_err(&pdev->dev,					"%s: failed to enable clock %d: %d\n",					__func__, i, ret);				clk_put(par->clks[i]);				par->clks[i] = NULL;			}		}	} 	return 0;} static void simplefb_clocks_destroy(struct simplefb_par *par){	int i; 	if (!par->clks)		return; 	for (i = 0; i < par->clk_count; i++) {		if (par->clks[i]) {			clk_disable_unprepare(par->clks[i]);			clk_put(par->clks[i]);		}	} 	kfree(par->clks);}#elsestatic int simplefb_clocks_init(struct simplefb_par *par,	struct platform_device *pdev) { return 0; }static void simplefb_clocks_destroy(struct simplefb_par *par) { }#endif static int simplefb_probe(struct platform_device *pdev){	int ret;	struct simplefb_params params;	struct fb_info *info;	struct simplefb_par *par;	struct resource *mem; 	if (fb_get_options("simplefb", NULL))		return -ENODEV; 	ret = -ENODEV;	if (dev_get_platdata(&pdev->dev))		ret = simplefb_parse_pd(pdev, &params);	else if (pdev->dev.of_node)		ret = simplefb_parse_dt(pdev, &params); 	if (ret)		return ret; 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);	if (!mem) {		dev_err(&pdev->dev, "No memory resource\n");		return -EINVAL;	} 	info = framebuffer_alloc(sizeof(struct simplefb_par), &pdev->dev);	if (!info)		return -ENOMEM;	platform_set_drvdata(pdev, info); 	par = info->par; 	info->fix = simplefb_fix;	info->fix.smem_start = mem->start;	info->fix.smem_len = resource_size(mem);	info->fix.line_length = params.stride; 	info->var = simplefb_var;	info->var.xres = params.width;	info->var.yres = params.height;	info->var.xres_virtual = params.width;	info->var.yres_virtual = params.height;	info->var.bits_per_pixel = params.format->bits_per_pixel;	info->var.red = params.format->red;	info->var.green = params.format->green;	info->var.blue = params.format->blue;	info->var.transp = params.format->transp; 	info->apertures = alloc_apertures(1);	if (!info->apertures) {		ret = -ENOMEM;		goto error_fb_release;	}	info->apertures->ranges[0].base = info->fix.smem_start;	info->apertures->ranges[0].size = info->fix.smem_len; 	info->fbops = &simplefb_ops;	info->flags = FBINFO_DEFAULT | FBINFO_MISC_FIRMWARE;	info->screen_base = ioremap_wc(info->fix.smem_start,				       info->fix.smem_len);	if (!info->screen_base) {		ret = -ENOMEM;		goto error_fb_release;	}	info->pseudo_palette = par->palette; 	ret = simplefb_clocks_init(par, pdev);	if (ret < 0)		goto error_unmap; 	dev_info(&pdev->dev, "framebuffer at 0x%lx, 0x%x bytes, mapped to 0x%p\n",			     info->fix.smem_start, info->fix.smem_len,			     info->screen_base);	dev_info(&pdev->dev, "format=%s, mode=%dx%dx%d, linelength=%d\n",			     params.format->name,			     info->var.xres, info->var.yres,			     info->var.bits_per_pixel, info->fix.line_length); 	ret = register_framebuffer(info);	if (ret < 0) {		dev_err(&pdev->dev, "Unable to register simplefb: %d\n", ret);		goto error_clocks;	} 	dev_info(&pdev->dev, "fb%d: simplefb registered!\n", info->node); 	return 0; error_clocks:	simplefb_clocks_destroy(par);error_unmap:	iounmap(info->screen_base);error_fb_release:	framebuffer_release(info);	return ret;} static int simplefb_remove(struct platform_device *pdev){	struct fb_info *info = platform_get_drvdata(pdev);	struct simplefb_par *par = info->par; 	unregister_framebuffer(info);	simplefb_clocks_destroy(par);	framebuffer_release(info); 	return 0;} static const struct of_device_id simplefb_of_match[] = {	{ .compatible = "simple-framebuffer", },	{ },};MODULE_DEVICE_TABLE(of, simplefb_of_match); static struct platform_driver simplefb_driver = {	.driver = {		.name = "simple-framebuffer",		.of_match_table = simplefb_of_match,	},	.probe = simplefb_probe,	.remove = simplefb_remove,}; static int __init simplefb_init(void){	int ret;	struct device_node *np; 	ret = platform_driver_register(&simplefb_driver);	if (ret)		return ret; 	if (IS_ENABLED(CONFIG_OF_ADDRESS) && of_chosen) {		for_each_child_of_node(of_chosen, np) {			if (of_device_is_compatible(np, "simple-framebuffer"))				of_platform_device_create(np, NULL, NULL);		}	} 	return 0;} fs_initcall(simplefb_init); MODULE_AUTHOR("Stephen Warren <swarren@wwwdotorg.org>");MODULE_DESCRIPTION("Simple framebuffer driver");MODULE_LICENSE("GPL v2");